The point is, the moon's orbit doesn't care whether the planet is tidally locked or not. Whether the planet is spinning like a top or not rotating at all, it's just a fixed source of gravity as far as the moon is concerned.Yes but I was referring to the situation if the planet was tidally locked therefore as it moved round it's orbit the orientation with respect to the star would be constant. Of course the moon would have to be in a circumpolar orbit I suppose and I don't know how possible this combination might be, my maths isn't up to it these days (if it ever was!) but I suspect gravitationally it wouldn't work. Naturally the moon wouldn't be tidally locked I suppose but that wasn't what I was referring to.